Bleeding for almost 3 weeks

So I’ve been on birth control for about a year now. It was the Blisovi 24 Fe and they switched the name to Hailey 24 Fe. I’ve been on Hailey for 7 months now. I missed ONE pill 2.5 weeks ago and I’ve been bleeding on and off ever since. At first it was like a normal period, then super heavy, then like a normal period again and then it went brown (TMI I know) but then it stopped for a few days and now I’m bleeding bright red again. Anyone have any advice or know what could be causing it? There’s also no way I could be pregnant. My tubes are tied and I’m only on the birth control to prevent periods all together. I’m also going to call my doctor in the morning if I’m still bleeding when I wake up. Just wanted to see if anyone knew what it could be.